Apparatus for Mechanical Treatment of Surfaces

ABSTRACT

Herein is described an apparatus for the mechanical treatment of surfaces comprising a wand ( 1 ), a head ( 2 ) that is movably fastened to the wand ( 1 ), a tool drive pad ( 3 ) attached in a rotatable manner to the head ( 2 ), a drive unit ( 4 ) for the drive of the tool drive pad ( 3 ), and a flexible shaft ( 5 ) that connects said tool drive pad ( 3 ) to the drive unit ( 4 ). According to the invention it is provided that the wand ( 1 ) ends at a distance from the head ( 2 ) and that the head ( 2 ) is held by a carrier hose ( 7 ) attached to the wand ( 1 ) which, during operation, transfers the transverse and tensile loads exerted upon the wand ( 1 ) to the head ( 2 ).

The invention relates to an apparatus for the mechanical treatment of surfaces with the features set forth in the preamble of claim 1. Such an apparatus is known from DE 20 2005 011 659 U1.

The known apparatus is a sander provided with a head, a wand affixed in a swiveling manner at the head, with at least one tool drive pad mounted in a pivotable manner at the head, a drive mechanism for the tool drive pad, and a hood that covers said tool drive pad. Such an apparatus helps construction workers and handymen for the treatment of surfaces, especially of walls and ceilings in buildings.

The single-axis joint by means of which the wand is connected to the hood of the sander facilitates the movement of the head piece of the sander along walls and above one's head on ceilings. The replacing of a single-axis joint with a biaxial joint such as, e.g., a cardan joint such as disclosed in DE 20 2005 011 U1 and in EP 0 727 281 B1 constitutes an even greater improvement.

Such apparatus are especially used for the smoothing of coatings on walls, ceilings and floors such as, e.g., plaster. For this it is important to guide the apparatus over the surface to be treated in such manner that the rotatable tool, in particular a sanding disk, actuates with a constant pressure distribution upon the surface to be treated, running as silently as possible. In this respect, the known apparatus require improvement.

The present invention has the object to improve an apparatus of above-mentioned type and, in particular, to facilitate the movement of such an apparatus and the obtaining of a constant pressure distribution of the tool actuating upon surfaces that are hard to reach such as, e.g., where a wall and a ceiling meet.

This task is solved by an apparatus with the features set forth in patent claim 1. Advantageous embodiments of the invention are object of the dependent claims.

In the apparatus for the mechanical treatment of surfaces according to the invention, the wand ends at a distance from the head. The head is held by a carrier hose attached to the wand, which hose during operation by a user, transfers pushing and pulling forces to the head in order to work, e.g., on a ceiling and to exert pressure on the head of the mechanical surface treatment apparatus by means of the wand via the carrier hose, so that a sanding or polishing means affixed to the tool drive pad can actuate upon the ceiling.

The head is mounted flexibly to the wand by means of the carrier hose so that, while working, the orienting of the head relative to the wand can be easily adapted depending on the given requirements. In particular, it can be obtained that the head can be tilted in any given direction. Thus, with an apparatus according to the invention it is much easier to work in particular on ceilings and corners between walls or ceilings.

Thus, the apparatus according to the invention can be used for varied tasks such as, e.g., by plasterers for the smoothing of plaster; by painters for the removal of old coats of paints and for the smoothing of walls for a new coat of paint; by paper-hangers for the removal of old wallpaper and for the smoothing of walls for new wallpaper; by floor layers for the scraping off of old remnants of glue and for the smoothing of the sub-flooring prior to the laying of a new floor covering; by wooden floor installers for the sanding of a laid wooden floor; by ironworkers for the smoothing of or rust removal from metal structures in or at a building or for the removal of coatings on metal surfaces, and for much, much more. Because of the ease of handling, the apparatus according to the invention is appropriate not only for craftsmen but also for handymen.

By way of example, the carrier hose can be a metal tube, especially a wrap hose. It is, however, also possible that the carrier hose is constituted by rings or tubing sections that are flexible with respect to each other, thus giving sufficient flexibility. Adequate rings or tubing sections can be made out of, e.g., metal or plastic.

The carrier hose is preferably configured in such a manner that at the tipping of the head it generates a restoring force with respect to the wand. In such a manner, the head always returns by itself to its original position. By way of example, the carrier hose can be a plastic tube that could be reinforced by a coiled spring. The carrier hose can also be a corrugated hose. In the case of a corrugated hose, additional measures for stiffening can be advantageously omitted, so that in such a manner it is possible to advantageously obtain an appropriate bending strength which, during the treating of a ceiling, prevents an unintentional tilting of the head while, on the other hand, it ensures the necessary flexibility required for the desired tilting for, e.g., the treating of a wall or floor surface. The length of the carrier hose between its mounting at the head and its mounting at the wand is between 4 cm and 15 cm, preferably 5 cm to 10 cm, in order to make possible an advantageous flexural rigidness and an ergonomic operation.

Preferably, the shaft runs through the carrier hose. In such a manner, the shaft is protected by the carrier hose. However, it is also possible to arrange the shaft next to the carrier hose.

Preferably, a suction tube for the suctioning off of dust created by treatment of surfaces carries the dust from the head to the wand, so that by means of a suction apparatus connected to the suction hose it is possible to considerably reduce the quantity of dust emitted. Preferably, the shaft runs through the suction hose. This results in an advantageously compact assembly. Another advantageous embodiment of the invention provides that the suction hose is configured as a bellows in a section adjacent to the head.

In such a manner, it is possible for the suction hose to easily follow all tilting movements of the head.

The wand is preferably hollow. Thus, it can house the flexible shaft that connects the tool drive pad with the drive unit. In such a manner, it is possible for the worker to carry the drive unit on his body or to put it on the floor. Advantageously, while handling the apparatus, the weight of the drive unit need not be absorbed by the wand. Preferably, in such an apparatus the shaft between the drive unit and the wand is surrounded by a protective hose. In order to protect the shaft against overbending, the protective hose is preferably provided with spaced annular segments. The thickness of the annular segments and their distance from each other allows presetting of the maximum possible bending radius of the protective hose.

Further details and advantages of the invention are hereinafter explained by using embodiments and making reference to the hereto attached drawings. Identical parts or parts corresponding to each other of the various embodiments are indicated by the same reference numbers. Herein

FIG. 1 shows an apparatus for the mechanical treatment of surfaces according to the invention;

FIG. 2 shows a detailed view of FIG. 1 in a partial sectional view;

FIG. 3 shows a variation of the embodiment illustrated in FIG. 1.

The apparatus for the mechanical treatment of surfaces illustrated in FIG. 1 comprises a wand 1 at which is affixed a head 2 in a movable manner. A tool drive pad 3, shown in FIG. 2, is rotatably mounted in the head 2. By way of example, a sanding or polishing device can be affixed to the tool drive pad 3. The tool drive pad 3 is driven by a drive unit 4 which by means of a flexible shaft 5 is connected to the tool drive pad 3. The shaft ends at a graduated socket 9 whose end, by way of example, is configured as a polygon, e.g., a square, and is seated in a polygonal bearing fit in a socket 13. A bearing fit is chosen in order to facilitate a longitudinal compensation. Between the sockets 9 and 13 is provided a ball bearing 14 for friction reduction.

The wand 1 comprises two wand sections 1 a, 1 b that are connected to each other by means of a lockable joint 6. The lockable joint allows the changing of the angle of the head with respect to the wand 1 so that, during operation, an adapting can be effectuated. The wand section 1 a facing the head is configured as a fork between whose prongs facing the head 2 the shaft 5 can swing at the tipping of the head 2 with respect to the wand 1. The wand section 1 b is provided with a handle 14 and a not shown mechanism for the unlocking of the articulated joint 6 such as, e.g., a control lever that can open a catch mechanism by means of a load cable.

The wand 1, in the herein illustrated embodiment its section 1 a, ends at a distance from the head 2. The head 2 is borne be a carrier hose 7, shown in FIG. 2, attached to the wand 1. The carrier hose 7 is in the illustrated embodiment a metal hose that has sufficient rigidity in order to transmit, during operation, pushing and pulling forces exerted upon the wand 1 to the head 2. In particular, due to the load exerted on the wand 1, the head 2 can be pressed against a ceiling via the carrier hose 7, so that the ceiling can be sanded.

The hose is flexible against a restoring force so that the position of the head 2 with respect to the wand 1 can be easily adapted to the characteristics of the surface to be treated. An advantageous flexural rigidness of the carrier hose 7 can be obtained by, e.g., that this hose is a wrap hose. In such a manner, the head 2 can be tipped with respect to the wand up to 180°, namely, until the head 2 abuts against the wand section 1 a which is configured as a fork. A clip 8 a, 8 b attaches the carrier hose 7 to the wand 1 as well as to the head 2. However, it can also be fastened, e.g., in an integral manner especially through gluing. It is also possible to sheathe one or both ends of the carrier hose 7 with a synthetic material and to use such synthetic material for the fastening. Especially when using a wrap hose, in such a manner is obtained an advantageous interlocking and an advantageous vibration absorption.

Between its fastening to the head, namely clip 8 b, and its fastening to the wand, namely clip 8 a, the length of the carrier hose 7 is 4 cm to 15 cm, especially 5 cm to 10 cm.

In the illustrated embodiment, the flexible shaft 5 runs through the carrier hose 7. The carrier hose 7 is surrounded by a suction hose 10 for the purpose of suctioning off dust generated by the sanding of the surfaces and that runs from a hood 16 of the head 2 to the wand 1. The wand 1 is configured as a tube over a portion of its length to which is attached the suction hose 10. At the opposite end of the head 2, the wand 1 is provided with a connecting sleeve 11 for a vacuum cleaner. The suction hose 10 and therefore also the surrounded shaft 5 can swing in the fork 1 a resulting in a compact and movable construction of the apparatus. The suction hose 10 is configured as a bellows 10 a in the area adjacent to the head 2 in order to follow the tipping movements of the head 2.

The dust suctioning hood 16 is continuously rotatable around its center axis and is open on one side. The lateral opening allows bringing the plate drive closer to a wall when treating a ceiling or a floor surface. The turnability of the hood 16 allows a turning of the opening to wherever it is needed.

The drive unit 4 of the illustrated embodiment can be worn on the body while working by, e.g., fastening to a belt or by setting it down on the floor. In such a manner, the weight of the drive unit 4 does not bother while working which is a special advantage when working on ceilings. The drive unit 4 is connected in a movable manner via the flexible shaft 5 to the wand 1. The shaft is surrounded by a protective hose 12 between the drive unit 4 and the wand 1. The protective hose 12 is provided with spaced annular segments. Because of their thickness and their distance from each other, the annular segments determine the greatest possible bending angle of the protective hose 12 thus protecting the shaft 5 against an overbending. By way of example, the annular segments of the protective hose 12 can be sheathed around the protective hose 12.

FIG. 3 shows a modification of the embodiment illustrated in FIG. 2, wherein in FIG. 3 for the sake of clarity the expansion bellows 10 a is not illustrated. Essentially, the embodiment illustrated in FIG. 3 differs from the embodiment shown in FIG. 2 only in that the flexible shaft 5, which comprises a shaft core 5 a and a shaft wrapping 5 b enclosing the shaft core 5, is provided with bearings 17 that surround the shaft core 5 a. The bearings 17 cause that the shaft core 5 a can advantageously frictionless rotate in the shaft wrapping 5 b. The bearings 17 are configured as antifriction bearings, namely as needle roller bearings. In principle, however it is also possible to use friction bearings.

In FIG. 3 are illustrated only two of the bearings 17 surrounding the shaft core 5 a. Preferably, the shaft 5 contains a greater number of such bearings, e.g., 5 to 20 bearings that are arranged at a distance of several centimeters, e.g., 5 cm to 10 cm, in the shaft 5. In such a manner it is possible to considerably reduce the friction between the shaft wrapping 5 b and the shaft core 5 a in the areas of the shaft 5 under stress because of bending. Such bearings 17 are especially advantageous in the area of the protective hose 12 surrounding the shaft 5.

REFERENCE NUMBERS

-   1 Wand -   1 a Wand section -   1 b Wand section -   2 Head -   3 Tool drive pad -   4 Drive unit -   5 Shaft -   5 a Shaft core -   5 b Shaft wrapping -   6 articulated Joint -   7 Carrier hose -   8 a Clip -   8 b Clip -   9 Socket -   10 Suction hose -   10 a Bellows -   11 Connecting sleeve -   12 Protective hose -   13 Socket -   14 Handle -   16 Hood -   17 Bearing 

1. An apparatus for the mechanical treatment of surfaces comprising a wand (1), a head (2) that is movably fastened at the wand (1), a tool drive pad (3) attached in rotatable manner to the head (2), a drive unit (4) for the driving of the tool drive pad (3) and a flexible shaft (5) that connects the tool drive pad (3) to the drive unit (4) characterized in that the wand (1) ends at a distance from the head (2) and that the head (2) is held by a carrier hose (7) attached to the wand (1) which, during operation, transfers to the head (2) pushing and pulling forces exerted upon the wand (1).
 2. An apparatus according to claim 1, characterized in that the shaft (5) comprises a shaft core (5 a) and a shaft wrapping (5 b) surrounding the shaft core (5 a), wherein the shaft core (5 a) is surrounded by at least one bearing (17) in the shaft wrapping.
 3. An apparatus according to claim 2, characterized in that the bearing (17) is an antifriction bearing, especially a needle roller bearing.
 4. An apparatus according to any of above claims, characterized in that the shaft (5) runs through the carrier hose (7).
 5. An apparatus according to any of above claims, characterized in that from the head (2) to the wand (1) runs a suction hose (10) for the suctioning off of dust generated by the treatment of surfaces.
 6. An apparatus according to claim 5, characterized in that the shaft (5) runs through the suction hose (10).
 7. An apparatus according to either claim 5 or 6, characterized in that the suction hose (10) surrounds the carrier hose (7).
 8. An apparatus according to any of the claims 5 to 7, characterized in that the suction hose (10) is configured as a bellows (10 a) in a section adjacent to the head (2).
 9. An apparatus according to any of above claims, characterized in that the carrier hose (7) is a corrugated hose.
 10. An apparatus according to any of above claims, characterized in that the carrier hose (7) is a metal hose.
 11. An apparatus according to any of above claims, characterized in that the wand (1) is provided with a handle (14).
 12. An apparatus according to any of above claims, characterized in that the wand (1) consists of two sections (1 a, 1 b) connected to each other by, an articulated joint (6).
 13. An apparatus according to claim 12, characterized in that the joint (6) is lockable.
 14. An apparatus according to claim 13, characterized in that a mechanism for unlocking of the locked joint (6) is attached on the section of the wand (1) opposite to the head (2).
 15. An apparatus according to any of the claims 12 to 14, characterized in that the articulated joint (6) is a single axis joint.
 16. An apparatus according to any of the claims 12 to 15, characterized in that the section (1 a) facing the head (2) has a length of less than ⅕, preferably less than ⅛, of the length of the second section (1 b) connected to it by the joint (6).
 17. An apparatus according to any of the claims 12 to 16, characterized in that the section (1 a) facing the head (2) is configured as a fork.
 18. An apparatus according to any of above claims, characterized in that the carrier hose (7) has a length of between 4 cm and 15 cm, preferably between 5 cm and 10 cm, between its fastening (8 b) at the head (2) and its fastening (8 a) at the wand (1).
 19. An apparatus according to any of above claims, characterized in that by means of the flexible shaft (5) the drive unit (4) is connected in a movable manner to the wand (1).
 20. An apparatus according to claim 19, characterized in that between the drive unit (4) and the wand (1) the flexible shaft (5) is surrounded by a protective hose (12).
 21. An apparatus according to claim 20, characterized in that the protective hose (12) is provided with spaced annular segments.
 22. An apparatus according to any of the claims 5 to 21, characterized in that the head (2) is provided with a dust suctioning hood (16) that has a lateral opening. 